A bipolar plate anode structure for PEM water electrolysis to produce hydrogen

Abstract

The utility model provides a PEM water electrolysis hydrogen production bipolar plate anode structure, including a water inlet, a hydrogen outlet, a flow zone, a sealing area, a flow field area, a positioning hole, a cover plate welding point and a water outlet, wherein the sealing area surrounds the flow field area, the water inlet, the water outlet and the flow zone. The utility model has the beneficial effects of: adopting a middle water inlet structure, on the one hand, making the distribution of water in the bipolar plate more uniform, avoiding the occurrence of water flow dead corners that affect the electrolysis efficiency, and on the other hand, making the oxygen generated by the anode be more quickly discharged along with the water flow, avoiding the defect of bubble accumulation.

Description

Technical Field

[0001] The utility model relates to the technical field of bipolar plates, in particular to an anode structure of a bipolar plate for producing hydrogen by electrolysis of water in a PEM. Background Art

[0002] The core materials of PEM electrolyzer are: proton exchange membrane, cathode and anode catalyst, cathode and anode gas diffusion layer and bipolar plate from inside to outside. As a very important component of PEM electrolyzer, bipolar plate brings together multiple functions such as gas, water flow, current and support. While providing structural support for PEM electrolyzer, it also provides a path for the supply of reactants and the discharge of products. For PEM water electrolysis, the heat and mass transfer of electrolyzer and the flow field structure operation process involve electrochemical reactions, and the heat and mass transfer phenomenon is very complex. The heat and mass transfer involved in the flow of fluid inside the electrolyzer in porous media (such as gas diffusion layer, catalyst layer) is affected by factors such as the microstructure of porous media, the interface interaction between fluid and wall, the interaction between different fluids and the bulk properties of fluids. In the current research process, the heat and mass transfer laws are generally analyzed, and the heat and mass transfer laws are specifically studied in combination with experiments. The shape structure of the flow field, the width and depth of the flow channel and the width of the ridge will directly affect the generation of hydrogen and oxygen and the heat and mass transfer effect in the electrolytic cell. In the flow field structure of PEM electrolyzer, the most commonly used flow field structures include parallel flow field, serpentine flow field, multi-serpentine flow field, interdigitated flow field, spiral flow field and mesh flow field. The researchers used high-speed optical imaging technology to study the anode flow field design and two-phase flow characteristics of single serpentine flow field and parallel flow field under different operating conditions, and found that the longer flow path length in the flow field leads to the formation of a ring flow state under high current density, which reduces the battery performance. In addition, many designs of the PEM electrolyzer during operation, such as the water supply method and water flow distribution path, also seriously restrict the improvement of water electrolysis efficiency. Utility Model Content

[0003] In order to overcome the above problems existing in the prior art, the utility model provides a PEM water electrolysis hydrogen production bipolar plate anode structure.

[0004] The utility model discloses a PEM water electrolysis hydrogen production bipolar plate anode structure, comprising a water inlet, a hydrogen outlet, a flow-averaging area, a sealing area, a flow field area, a positioning hole, a cover plate welding point and a water outlet, wherein the sealing area surrounds the flow field area, the water inlet, the water outlet and the flow-averaging area, the three sides of the water inlet are provided with sealing areas, the hydrogen outlets are four and of the same size, the hydrogen outlets are arranged at the four corners of the bipolar plate, and are respectively arranged on both sides of the water inlet and the water outlet.

[0005] On this basis, the flow equalizing area is arranged between the flow field area and the water inlet, and the flow equalizing area includes a diverter line, a guide line and a flow equalizing point. The diverter line, the guide line and the flow equalizing point are arranged in sequence. The diverter line is a raised parallelogram with a width of 0.5-2mm and a length of 2-5mm, and a raised depth of 0.2-0.8mm. The guide line is an "L"-shaped raised structure with a raised depth of 0.2-0.8mm. The flow equalizing point is an ellipse with a width of 0.5-2mm, a length of 1-4mm, a radius of 0.25-1mm, and a raised depth of 0.2-0.8mm.

[0006] On this basis, the sealing area is distributed with sealing line ridges and sealing line grooves, which are connected in sequence. The sealing line ridges are 0.2-0.5mm wide, the protrusion height is 0.2-0.4mm, the sealing line grooves are 0.2-0.5mm wide, and the recessed depth is 0.2-0.4mm.

[0007] On this basis, the flow field area is evenly distributed with flow field ridges and flow channel grooves, the flow field ridges and flow channel grooves are adjacent to each other, the flow field ridges are rectangular with a width of 0.5-2mm, a depth of 0.2-2mm, and a protrusion height of 0.2-2mm, and the width of the flow channel groove is 0.5-2mm.

[0008] On this basis, the cover plate welding point is at the water inlet, and the cover plate welding point is 0.1-0.35mm in depth and 2-4mm in size. 2 dots.

[0009] On this basis, the positioning holes are arranged at the four corners of the bipolar plate.

[0010] Compared with the prior art, the beneficial effects of the utility model are:

[0011] (1) The utility model adopts a structure of middle water inlet, which, on the one hand, makes the water more evenly distributed in the bipolar plate, avoiding the occurrence of water flow dead corners that affect the electrolysis efficiency; on the other hand, it also enables the oxygen generated by the anode to be discharged more quickly along with the water flow, avoiding the defect of bubble accumulation;

[0012] (2) The utility model makes the water flow more evenly distributed by using multiple structures in the flow equalization area, avoids the occurrence of eddy currents, turbulence, backflow and other phenomena that affect the movement of the fluid, and is more conducive to maintaining the pressure change of the water flow, so that the water flow pressure fluctuation does not significantly affect the electrolysis performance;

[0013] (3) The utility model adopts a line sealing method, so that the sealing plastic can be better embedded in the sealing area without defects such as displacement and leakage;

[0014] (4) The flow channel grooves and flow field ridges of the flow field area of ​​the utility model are obtained through theoretical calculations, and have better support and drainage effects, ensuring the water flux while having better reaction performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the bipolar plate of the utility model;

[0016] Figure 2 It is an enlarged schematic diagram of the structure of the anode water inlet equal flow area;

[0017] Figure 3 It is a schematic diagram of the cross-section structure;

[0018] In the figure: 1, water inlet, 2, hydrogen outlet, 3, equal flow area, 3-1, diversion line, 3-2, guide line, 3-3, equal flow point, 4, sealing area, 4-1, sealing line ridge, 4-2, sealing line groove, 5, flow field area, 5-1, flow field ridge, 5-2, flow channel groove, 6, positioning hole, 6-1, feed pipe, 6-2, discharge pipe, 7, cover plate welding point, 8, water outlet. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0020] The utility model discloses a bipolar plate anode structure for PEM water electrolysis hydrogen production, referring to Figure 1 , Figure 2 and Figure 3 , including a water inlet 1, a hydrogen outlet 2, a flow-averaging area 3, a sealing area 4, a flow field area 5, a positioning hole 6, a cover plate welding point 7 and a water outlet 8. The sealing area 4 surrounds the flow field area 5, the water inlet 1, the water outlet 8 and the flow-averaging area 3. The sealing area 4 is arranged on three sides of the water inlet 1. There are four hydrogen outlets 2 and they are all the same size. The hydrogen outlets 2 are arranged at the four corners of the bipolar plate and are respectively arranged on both sides of the water inlet 1 and the water outlet 8. The hydrogen outlet 2 is used to export the generated hydrogen.

[0021] The water enters through the water inlet 1 and adopts a middle water inlet structure. On the one hand, it makes the water more evenly distributed in the bipolar plate to avoid dead corners of water flow that affect the electrolysis efficiency. On the other hand, it also allows the oxygen generated by the anode to be discharged more quickly along with the water flow to avoid the defect of bubble accumulation.

[0022] The flow-equalizing area 3 is arranged between the flow field area 5 and the water inlet 1, and water passes through the flow-equalizing area 3 and the flow field area 5. The flow-equalizing area 3 includes a diverter line 3-1, a guide line 3-2 and a flow-equalizing point 3-3. The diverter line 3-1, the guide line 3-2 and the flow-equalizing point 3-3 are arranged in sequence. When designing the size, liquid diversion is taken into consideration. If it is too large, it will cause blockage, and if it is too small, it will not play the role of diversion. The diverter line 3-1 is a raised parallelogram with a width of 0.5-2mm and a length of 2-5mm, and a raised depth of 0.2-0.8mm. The guide line 3-2 is an "L"-shaped raised structure with a raised depth of 0.2-0.8mm. The flow-equalizing point 3-3 is an ellipse with a width of 0.5-2mm, a length of 1-4mm, a radius of 0.25-1mm, and a raised depth of 0.2-0.8mm.

[0023] By using multiple structures to evenly evenly evenly distribute the water flow in the evenly distributed flow area, it can avoid the occurrence of eddy currents, turbulence, backflow and other phenomena that affect the movement of the fluid, and it is more conducive to maintaining the pressure change of the water flow, so that the water flow pressure fluctuation will not significantly affect the electrolysis performance.

[0024] The flow field area 5 is evenly distributed with flow field ridges 5-1 and flow channel grooves 5-2. The flow field ridges 5-1 and flow channel grooves 5-2 are adjacent to each other. The flow field ridges 5-1 are rectangular with a width of 0.5-2mm, a depth of 0.2-2mm, and a protrusion height of 0.2-2mm. The width of the flow channel grooves 5-2 is 0.5-2mm.

[0025] The sizes of the flow field ridge 5-1 and the flow channel groove 5-2 are obtained through simulation calculations based on the size of the passing area and the tributaries, and have better support and drainage effects, ensuring the water flux while having better reaction performance.

[0026] The sealing area 4 is provided with sealing line ridges 4-1 and sealing line grooves 4-2, which are connected in sequence. The sealing line ridges 4-1 are 0.2-0.5mm wide and 0.2-0.4mm high. The sealing line grooves 4-2 are 0.2-0.5mm wide and 0.2-0.4mm deep.

[0027] The line sealing method is adopted so that the sealing plastic can be better embedded in the sealing area without defects such as displacement and air leakage.

[0028] The cover plate welding point 7 is at the water inlet 1, and the cover plate welding point 7 is 0.1-0.35mm in depth and 2-4mm in size. 2 The dot serves as a transition between the water inlet 1 and the uniform flow area 3.

[0029] Positioning holes 6 are provided at the four corners of the bipolar plate to position the plate during assembly and prevent misalignment.

[0030] Finally, the oxygen produced by the mixed anode flows out from the water outlet 8 .

[0031] In the description of the present invention, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0032] In the present utility model, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation", "screwing", "pad installation" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the utility model according to the specific circumstances.

[0033] The above description shows and describes the preferred embodiments of the utility model. As mentioned above, it should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the utility model concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.

Claims

1. A PEM water electrolysis hydrogen production bipolar plate anode structure, characterized by: The bipolar plate comprises a water inlet (1), a hydrogen outlet (2), a flow-averaging area (3), a sealing area (4), a flow field area (5), a positioning hole (6), a cover plate welding point (7) and a water outlet (8); the sealing area (4) surrounds the flow field area (5), the water inlet (1), the water outlet (8) and the flow-averaging area (3); the sealing area (4) is arranged on three sides of the water inlet (1); there are four hydrogen outlets (2) of the same size; the hydrogen outlets (2) are arranged at the four corners of the bipolar plate and are respectively arranged on both sides of the water inlet (1) and the water outlet (8).

2. The PEM water electrolysis hydrogen production bipolar plate anode structure according to claim 1, characterized in that: The flow balancing area (3) is arranged between the flow field area (5) and the water inlet (1), and the flow balancing area (3) comprises a flow dividing line (3-1), a flow guiding line (3-2) and a flow balancing point (3-3). The flow dividing line (3-1), the flow guiding line (3-2) and the flow balancing point (3-3) are arranged in sequence. The flow dividing line (3-1) is a raised parallelogram with a width of 0.5-2 mm and a length of 2-5 mm, and a raised depth of 0.2-0.8 mm. The flow guiding line (3-2) is an "L"-shaped raised structure with a raised depth of 0.2-0.8 mm. The flow balancing point (3-3) is an ellipse with a width of 0.5-2 mm, a length of 1-4 mm, a radius of 0.25-1 mm, and a raised depth of 0.2-0.8 mm.

3. The PEM water electrolysis hydrogen production bipolar plate anode structure according to claim 1, characterized in that: The sealing area (4) is provided with a sealing line ridge (4-1) and a sealing line groove (4-2), the sealing line ridge (4-1) and the sealing line groove (4-2) are connected in sequence, the sealing line ridge (4-1) has a width of 0.2-0.5 mm and a protrusion height of 0.2-0.4 mm, the sealing line groove (4-2) has a width of 0.2-0.5 mm and a recessed depth of 0.2-0.4 mm.

4. The PEM water electrolysis hydrogen production bipolar plate anode structure according to claim 1, characterized in that: The flow field area (5) is evenly distributed with flow field ridges (5-1) and flow channel grooves (5-2); the flow field ridges (5-1) and the flow channel grooves (5-2) are adjacently distributed; the flow field ridges (5-1) are rectangular parallelepiped with a width of 0.5-2 mm, a depth of 0.2-2 mm, and a protrusion height of 0.2-2 mm; and the width of the flow channel grooves (5-2) is 0.5-2 mm.

5. The PEM water electrolysis hydrogen production bipolar plate anode structure according to claim 2, characterized in that: The cover plate welding point (7) is located at the water inlet (1), and the cover plate welding point (7) has a depth of 0.1-0.35 mm and a size of 2-4 mm. 2 dots.

6. The PEM water electrolysis hydrogen production bipolar plate anode structure according to claim 2, characterized in that: The positioning holes (6) are arranged at the four corners of the bipolar plate.

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